1. Field of the Invention
The present invention relates to a disposable mask for dust protection. More particularly, the disposable mask for dust protection guarantees freedom of movement while maintaining adhesive force even when the wearer speaks or moves their jaw, maintains tension on the strap, and enables easy adjustment of the length of the strap.
2. Related Prior Art
Generally, a lot of dust is generated in areas such as paper mills, textile factories, quarries, and the like, and large quantities of poisonous gases are generated in areas such as various chemical processing plants, welding processing factories, metal processing factories, plating factories, and the like. Since, in the event that a worker continuously inhales dust and poisonous gases, the dust and poisonous gases can cause respiratory diseases in organs, such as the lungs, throat, nose, and the like, which may be fatal, workers wear a dust protective mask in order to protect themselves from these harmful substances.
There are various types of dust protective masks, e.g., a dust protective mask containing a purifying agent, or a dust protective mask with filter paper installed therein. However, these dust protective masks are expensive, and furthermore, the purifying agent must be exchanged every 3 or 4 days. Moreover, since the above-mentioned dust protective masks do not sufficiently filter the dust or poisonous gases, disposable dust protective masks are usually used when the workers' health must be guaranteed.
The conventional dust protective mask (hereinafter referred to as a “mask”) includes a filter made of non-woven fabric and straps connected to the filter.
Since the mask must be discarded after wearing once, it has a limited ability to filter dust present in the air, and the like.
Other masks have been proposed to overcome the above-mentioned shortcoming. For example, the conventional mask includes a folded filter and straps connected to both sides of the filter by means of high frequency sewing. The folded filter is made by bending a front side of the mask several times and by finishing both ends thereof.
According to the above-mentioned mask, the filter is uniformly attached to the nose and lower side of the jaw of the user while the filter is unfolded, so that the efficiency of dust filtering may be increased. However, when the filter is unfolded upward and downward, central portions of the sides of the filter are bent, so that a gap is formed between the user's face and the mask. Thus, the filtering capacity is deteriorated.
There is another mask proposed to overcome the drawbacks. The mask includes a filter having folding portions provided at the upper and lower sides of the filter and finishing portions at both sides of the filter, adjustable straps installed in the respective finishing portions, and a pressing device coupled to the folding portions.
According to the above-mentioned mask, the upper and lower folding portions are unfolded when wearing the mask, and, at the same time, the upper and lower folding portions are closely attached to the user's nose and the lower side of the jaw. The finishing portions of the filter are not folded, and the filter is closely attached to the user's cheeks. Thus, the filtering efficiency can be increased. However, since the upper and lower folding portions of the filter have sufficient restoring elasticity, the unfolded shape when wearing the mask is unstable. Moreover, if the user moves their mouth and/or jaw when wearing the mask, the initial fit of the mask is changed so that the gap between the mask and the user's face is gradually increased.
Further, since the conventional mask employs a metal plate pressing device or a wire-shaped pressing device attached to the folding portions, the pressing device is not closely attached to the user's face, allowing it to easily become unfastened.
There are shortcomings in other conventional masks as well. Since the conventional mask is manufactured assuming that the user keeps their mouth closed and does not move their jaw when wearing the mask, the conventional mask may be stably attached to the user's face when the user has their mouth closed and does not move their jaw. However, if the user moves their jaw in order to have a conversation or to move their lips when wearing the mask, since there is no space in the conventional mask, the conventional mask must be moved up, down, right, or left. For this reason, there is formed a gap where dust flows in between the user's face and the mask. Therefore, it is inconvenient to adjust the position of the conventional mask in order to prevent dust from entering.
Meanwhile, according to the conventional mask, the length of the straps can be adjusted in accordance with the contours and size of the user's face, but there is no special means for adjusting the length of the straps. Since the length of the straps is adjusted by tying the straps, it is inconvenient to repeat the tying and untying of the straps depending on the contours of the user's head when wearing and taking off the conventional mask, or adjusting the length of the straps.